1. Field of the Invention
The present invention is directed to a surface mountable miniature incandescent light assembly, and more particularly to a surface mountable miniature incandescent light assembly in which all seals are glass to metal seals of substantially cylindrical configuration.
2. Brief Description of the Prior Art
Miniature incandescent lights have many applications in electronic and like appliances and equipment, with digital watches serving as a primary example. It is generally recognized in the art that for economy of manufacture the miniature incandescent lights must be adapted for surface mount technology, that is the miniature incandescent lights must be capable of being incorporated in equipment (such as an electronic watch) in an electronic assembly line without the need of soldering or welding connections to a circuit board.
Miniature incandescent lights of the prior art are, however, primarily designed for mounting to circuit boards by soldering, and to this end the prior art miniature lights usually incorporate wires which extend from two ends of a light assemby of elongated shape. A prior art miniature incandescent light design of which the present inventor is aware, and which is said to be adapted for surface mount technology, has an elongated cylindrical envelope for an incandescent filament and open cylindrical metal end caps mounted to the envelope. Leads extend from the envelope through resilient pliable material to connect with the end caps.
A disadvantage of the miniature incandescent lights of the prior art, of which the present inventor is aware, that the lights contain seals where wires penetrate glass, or glass-to-metal seals which do not have a relatively extended surface area. Because miniature incandescent lights are evacuated (contain vacuum) to minimize heat loss in the filament, efficient seals are important. The present invention provides a miniature incandescent light assembly which is highly adapted for surface mount technology, and which has only glass-to-metal seals of relatively extended surface area of substantially cylindrical configuration.